Recent advances in genome sequencing techniques and analysis methods have significantly accelerated the ability to catalog and map genetic factors associated with a diverse range of biological functions and diseases. Precise genome targeting technologies are needed to enable systematic reverse engineering of causal genetic variations by allowing selective perturbation of individual genetic elements, as well as to advance synthetic biology, biotechnological, and medical applications. Although genome-editing techniques such as designer zinc fingers, transcription activator-like effectors (TALEs), or homing meganucleases are available for producing targeted genome perturbations, there remains a need for new genome engineering technologies that are affordable, easy to set up, scalable, and amenable to targeting multiple positions within the eukaryotic genome.
Double stranded breaks (DSBs) represent a major threat to the stability of the genome, and unrepaired DSBs can result in potentially oncogenic chromosomal deletions, amplifications, and translocations. DSBs can be caused by exogenous agents (ionizing radiation; chemicals, including various agents used in anti-cancer chemotherapy) as well as by endogenous processes (metabolic reactive oxygen by-products; replication fork collapse). Recently, genome-editing nucleases have emerged as a highly relevant potential cause of undesired, off-target DSBs. There is currently a growing interest in different research fields in developing methods that can portrait the genome-wide landscape and precise location of DSBs under various conditions: